Static gas pressure measuring device

ABSTRACT

Apparatus for measuring the gas permeability of a porous layer of material in which provision is made for contacting the surface of the porous layer of material with the downwardly directed open end of a tubular element, the other end of which is in communication with a gas pressure measuring device, while isolating an area of the surface of the porous layer of material surrounding the open end of the tubular element from the ambient atmosphere by means of an imperforate chamber which has a downwardly directed opening, the rim of which makes continuous contact with the surface of the porous layer of material all around the opening of the tubular element. Where the area of contact of the rim of the opening of the chamber with the surface of the porous layer of material is appreciably greater than the area of contact of the open end of the tubular element with the surface of the layer of porous material, provision is made for exerting a greater total pressure on the surface of the porous layer of material by the rim of the chamber than by the open end of the tubular element.

United States Patent Jakimowicz June 17, 1975 STATIC GAS PRESSURE MEASURING [57] ABSTRACT DEVICE Apparatus for measuring the gas permeability of a po- [75] Inventor: Christopher C. Jakimowicz, Detroit, rous layer of material in which provision is made for Mich. contacting the surface of the porous layer of material [73] Assignee: National Steel Corporation, with the downwardly directeq end of a F i Pittsbur h P element, the other end of wh1ch 1s 1n eommunlcation I w1th a gas pressure measuring dev1ce, wh1le isolating [22] Filed: May 15, 1974 an area of the surface of the porous layer of material surrounding the open end of the tubular element from [21] Appl' 470ll7 the ambient atmosphere by means of an imperforate chamber which has a downwardly directed opening,

[52] U.S. Cl. 73/38 the rim of which makes continuous contact with the [51] Int. Cl. GOln 15/08 surface of the porous layer of material all around the [58] Field of Search 73/38, 19,40, 40.5 R, opening of the tubular element. Where the area of 73/453, 46 contact of the rim of the opening of the chamber with the surface of the porous layer of material is apprecia- [56] References Cited bly greater than the area of contact of the open end of UNITED STATES PATENTS the tubular element with the surface of the layer of 3,056,281 10/1962 Smyth 73/38 Porous material Provision is made for exerting a 3,548,635 12/1970 Hutchinson etal 73/38 greater total Pressure on the Surface of the Porous Primary ExaminerDonald O. Woodiel Attorney, Agent, or Firm-Shanley, ONeil and Baker GAS layer of material by the rim of the chamber than by the open end of the tubular element.

7 Claims, 2 Drawing Figures STATIC GAS PRESSURE MEASURING DEVICE BACKGROUND OF THE INVENTION In sintering operations, for example the sintering of blast furnace fines, for most efficient operation, it is necessary to arrive emperically at the dynamic and static gas pressure conditions in and around the sinter bed. Especially important is the sinter bed top static pressure. Variations in the pressure take place due to variations in the depths of the layer of material to be sintered and also due to variations in time elapsed after initial ignition of the coke breeze or carbonaceous material in the bed. There has been no simple device for measuring accurately this sinter bed top static pressure.

Applicants invention supplies this need in a simple and efficient manner.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING FIG. 1 is a partially diagrammatic view with parts in section better to illustrate the invention, and

FIG. 2 is a fragmentary view, partly diagrammatic, with parts in section of a modification of a device similar to that illustrated in FIG. 1.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION Referring to FIG. 1, the pallet ofa sintering machine is shown at carrying a bed 12 of pulverulent material to be sintered. The material in this bed can be iron ore fines, flue dust and coke breeze or any other pulverulent material which forms a porous bed or layer of material through which ambient air is drawn by the presence of a subatmospheric gas pressure in the space 14 below pallet 10. The top surface of the porous layer of material is indicated by reference numeral 16.

An embodiment of the apparatus of the present invention is indicated generally by reference numeral and is made up of a pipe or conduit indicated generally at 21, an open ended chamber indicated generally at 22 and a gas pressure measuring system indicated generally at 23. The conduit 21 is shown made up of a section 24 which may be a conventional one-quarter inch galvanized pipe nipple, 3 or 4 inches long, and a section 26 which may be a conventional three-eighths inch galvanized pipe nipple, about 2 inches long, the two sections connected by a conventional galvanized, concentric reducer 25. Carried by the lower end portion of conduit section 26 is a large washer 28 and a nut 29 screwed on to the threads of conduit section 26, the connection between nut 29 and the screw threads of nipple 26 being gas tight. The lower end of nipple 26 constitutes a porous layer contacting means having tubular wall means including nut 29. The lower face 30 of nut 29 forms an opening with the lower face of nut 29 presenting a surface for contacting the surface 16 of the porous layer of material 12.

Carried on conduit 21 is the bell of a conventional rubber plunger or plumbers helper which forms the downwardly directed open bottom chamber 22. A gastight seal is formed between chamber 22 and conduit 21 by dimensioning nipple 26 and washer 28 so that tightening up nut 30 will compress the upper part of the bell between washer 28 and the lower end of reducer 25.

The upper end of conduit 21 is connected to gas pressure measuring system 23. This is by means of a standard coupling 32 and a packing gland 34, 35 to the flexible, plastic tubing 36 of the gas pressure measuring system, which can be one-eighth inch internal diameter. The plastic tubing goes to a gas pressure measuring device, such as a monometer, shown diagrammatically at 38.

In use, the apparatus of FIG. 1 is grasped at pipe 24 by an operator and the bottom edge 40 of chamber 22 is placed in contact throughout its circumferential length with the surface of the porous layer the permeability of which is to be measured. The lower surface of nut 30 which forms the effective opening at the lower end of conduit 22 is designed to act as the means for picking up the static gas pressure at the surface 16 of the porous layer for delivery to the gas measuring device by being brought into contact with surface 16 throughout its circumferential edge. Dotted lines in FIG. 1 show how this is accomplished. The resiliently flexible walls of bell 31 are distorted in a downward direction to bring porous layer contacting means 30 into contact with surface 16. As is shown by the dotted lines, the resilient resistance of the walls of bell 31 to deformation causes the lower edge 40 of bell 31 to sink into the porous layer as illustrated at 42 thereby slightly compressing the porous material at that point to make an effective sealing contact with the surface 16 of the porous layer of bed 12. At the same time the surface 30 of nut 29 acts as the porous layer contact means by coming into similar contact with the surface 16.

The apparatus just described gives a very accurate measurement of the static pressure at the surface 16 because chamber 22 by means of the sealing effect of edge 40, the spacing of edge 40 from edge 30 and the gas-tight relationship of chamber 22 with conduit 20 all contribute to form a body of quiescent gas surrounding the edge 30 of the static pressure measuring opening into conduit 21 and the system 23. If the lower end of conduit 26 has the porous layer contacting means 30 pressed against the surface 16 without the protection of chamber 22, the movement of air in the vicinity of means 30 will deleteriously affect the static pressure measurement within the orifice surrounded by means 30.

The plane of edge 30 of the pressure measuring means could be permanently positioned in the same plane as the plane of the edge 40 but the positioning of edge 30 relative to surface 16 is critical and the proper position of edge 30 might not give an adequate sealing action at edge 40. To form an effective seal at edge 40, edge 40 is preferably wide so as to make contact with a large area of surface 16. This in turn presents the problem of edge 40 being pressed against surface 16 with sufficient pressure to make a good seal. The present invention achieves this good seal by virtue of the resilience of the walls 31 of chamber 21, whereby edge 40 of relatively great area is pressed against surface 16 with a greater total pressure than the total pressure exerted by the smaller area of edge 30 pressing on the surface 16.

MODIFICATION OF FIGURE 2 In describing the modification illustrated in FIG. 2, where it would lead to simplification of the specification, the same reference numerals are used for the same parts as are used in FIG. 1 but in such cases the reference numerals are primed in FIG. 2.

In this modification the walls 31' of chamber 22' can be rigid if desired and sections 24' and 26' of conduit 21 can be formed integral and of the same diameter. In this modification reducer 25 of FIG. 1 is replaced by a packing gland structure indicated generally at 50 which slideably receives the unitary pipe resulting from making sections 24 and 26 integral. The body 52 of the packing gland structure is fixedly attached to the uppermost portion of chamber 22 with the connection being gas tight. Packing gland nut 54 puts only sufficient pressure on the packing (not shown) as will maintain a gas-tight seal but will permit pipe 24', 26 to slide freely up and down along the longitudinal axis of pipe 24, 26'. By means of this construction, the lower end portion of pipe 26 and the associated edge 30 of the opening of nut 29 can be lowered with the plane of edge 30 remaining parallel to the plane of edge 40' so that an operator can bring edge 30 into contact with the surface of a porous layer of material when edge 40 is making sealing contact with such a surface. A tension spring 56 has its upper end attached to the body 52 of the packing gland and its lower extremity attached to the lowermost end of pipe portion 26'. The tension of this spring can assist in returning pipe 24', 26' to retracted position while at the same time be so weak as not to affect appreciably the relative pressures exerted on edges 30' and 40' by an operator during use of the device. If desired, the tension of spring 56 can be designed so as to accomplish the same purposes as the resilience of the walls 31 of the chamber 22 in the FIG. 1 embodiment but with the capability of better resilience control. This is because where desired, the tension spring 56 can be designed to have less, equal or greater resilience than the walls 31 of chamber 22, thereby having this advantage over the FIG. 1 embodiment.

In use, the apparatus of FIG. 2 operates in the same manner as the embodiment illustrated in FIG. 1 except that the edge 40 is pressed against a surface 16 with substantially the same total pressure as edge 30 is pressed against sruface 16 when tension spring 56 is designed to act merely as a stop or so as to have only sufficient resilience to return conduit means 21 to its inoperative position after the apparatus has been in use with both edges 30 and 40' in contact with a surface 16 of a porous layer of material.

It will be noted that in both disclosed embodiments the plane of edges 30 and 30 are parallel to the plane of edges 40 and 40, respectively, at all times although the only time this is critical is when these edges are in contact with the porous layer surface 16.

An important feature of the present invention is the spacing between edges 40 or 40 and 30 or 30', respectively, to form a chamber around edges 30 or 30 which will result in a body of quiescent air or gas surrounding edges 30 or 30'. In the claims the spatial relationship of edges 40 or 40 to edges 30 or 30' is described as concentric but the surfaces need not be circular and the spaced relationship can be approximate.

I claim:

1. An apparatus for measuring the permeability of a porous layer of material comprising a. conduit means having two open ends,

gas pressure measuring means connected to one open end of the conduit means,

c. chamber means having imperforate wall means,

the chamber means being carried by and in gastight connection with the conduit means,

(I. margins on the wall means forming a large opening into the chamber means, the large opening being spaced from the chamber means connection with the conduit means,

e. the margins of the wall means forming the opening in the chamber means having a continuous edge completely surrounding the opening, the continuous edge throughout its entire length lying in a single plane,

f. porous layer contacting means having tubular wall means carried by the conduit means and in gastight connection with the other open end of the conduit means, the porous layer contacting means projecting into the chamber,

g. margins on tubular wall means of the porous layer contacting means forming an opening facing in the same general direction as the large opening in the chamber means, the opening of the porous layer contacting means being small compared to the opening of the chamber means and the edge surrounding the porous layer contacting means opening being spaced inwardly of the edge surrounding the chamber means opening in a direction away from the plane of the edge of the opening of the chamber means,

h. the margins on the wall means forming the opening in the porous layer contacting means having a continuous edge completely surrounding the opening, the continuous edge throughout its entire length lying in a single plane, and

i. means acting between the margins of the wall means of the chamber means and the margins of the wall means of the conduit means providing for relative movement of the edge of the opening of the porous layer contacting means toward the edge of the opening of the chamber means to bring the edge of the opening of the chamber means and the edge of the opening of the porous layer contacting means into simultaneous contact with the surface of a porous layer of material for measuring the permeability thereof with the edges of the two openings approximately concentric and each of the edges of the two openings in continuous contact with the surface of the porous layer throughout the entire length of the edge.

2. The apparatus of claim 1 in which the means of limitation (i) include resilient means acting to exert a greater total pressure on the edge of the opening of the chamber means than the total pressure exerted on the edge of the opening of the porous layer contacting means when the two openings are in contact with the porous layer.

3. The apparatus of claim 1 in which relative move ment' of the edge of the opening of the porous layer contacting means and the edge of the opening of the chamber means is along an axis of symmetry common to the chamber means and the porous layer contacting means.

4. The apparatus of claim 1 in which the planes described in limitations (e) and (g) are parallel.

S. The apparatus of claim 1 in which the means of limitation (i) include a rigid connection between the chamber means and the conduit means and include resiliently flexible portions in the wall means of the chamher means extending entirely around the porous layer contacting means to provide for continued movement of the porous layer contact means toward a porous layer of material after contact of the edge of the margins of the wall means of the chamber means with the porous layer of material to bring the edge of the margins of the wall means of the porous layer contacting means into contact with the porous layer of material while maintaining the edge of the margins of the wall means of the chamber means pressed against the porous layer of material with a pressure greater than that exerted on the porous layer of material by the edge of the porous layer contacting means.

6. The apparatus of claim 1 in which the wall means of the chamber means are formed of rigid material and the means of limitation (i) include a gas-tight sliding connection between the chamber means and the conduit means to provide for continued movement of the porous layer contact means toward a porous layer of material after contact of the edge of the margins of the wall means of the chamber means with the porous layer of material to bring the edge of the margins of the wall means of the porous layer contacting means into contact with the porous layer of material.

7. The apparatus of claim 6 in which the gas-tight sliding connection between the chamber means and the conduit means includes resilient means acting between the chamber means and the porous layer contact means for maintaining the edge of the margins of the wall means of the chamber means pressed against the porous layer of material with a pressure greater than that exerted on the porous layer of material by the edge of the porous layer contacting means.

* l =I= l= 

1. An apparatus for measuring the permeability of a porous layer of material comprising a. conduit means having two open ends, gas pressure measuring means connected to one open end of the conduit means, c. chamber means having imperforate wall means, the chamber means being carried by and in gas-tight connection with the conduit means, d. margins on the wall means forming a large opening into the chamber means, the large opening being spaced from the chamber means connection with the conduit means, e. the margins of the wall means forming the opening in the chamber means having a continuous edge completelY surrounding the opening, the continuous edge throughout its entire length lying in a single plane, f. porous layer contacting means having tubular wall means carried by the conduit means and in gas-tight connection with the other open end of the conduit means, the porous layer contacting means projecting into the chamber, g. margins on tubular wall means of the porous layer contacting means forming an opening facing in the same general direction as the large opening in the chamber means, the opening of the porous layer contacting means being small compared to the opening of the chamber means and the edge surrounding the porous layer contacting means opening being spaced inwardly of the edge surrounding the chamber means opening in a direction away from the plane of the edge of the opening of the chamber means, h. the margins on the wall means forming the opening in the porous layer contacting means having a continuous edge completely surrounding the opening, the continuous edge throughout its entire length lying in a single plane, and i. means acting between the margins of the wall means of the chamber means and the margins of the wall means of the conduit means providing for relative movement of the edge of the opening of the porous layer contacting means toward the edge of the opening of the chamber means to bring the edge of the opening of the chamber means and the edge of the opening of the porous layer contacting means into simultaneous contact with the surface of a porous layer of material for measuring the permeability thereof with the edges of the two openings approximately concentric and each of the edges of the two openings in continuous contact with the surface of the porous layer throughout the entire length of the edge.
 2. The apparatus of claim 1 in which the means of limitation (i) include resilient means acting to exert a greater total pressure on the edge of the opening of the chamber means than the total pressure exerted on the edge of the opening of the porous layer contacting means when the two openings are in contact with the porous layer.
 3. The apparatus of claim 1 in which relative movement of the edge of the opening of the porous layer contacting means and the edge of the opening of the chamber means is along an axis of symmetry common to the chamber means and the porous layer contacting means.
 4. The apparatus of claim 1 in which the planes described in limitations (e) and (g) are parallel.
 5. The apparatus of claim 1 in which the means of limitation (i) include a rigid connection between the chamber means and the conduit means and include resiliently flexible portions in the wall means of the chamber means extending entirely around the porous layer contacting means to provide for continued movement of the porous layer contact means toward a porous layer of material after contact of the edge of the margins of the wall means of the chamber means with the porous layer of material to bring the edge of the margins of the wall means of the porous layer contacting means into contact with the porous layer of material while maintaining the edge of the margins of the wall means of the chamber means pressed against the porous layer of material with a pressure greater than that exerted on the porous layer of material by the edge of the porous layer contacting means.
 6. The apparatus of claim 1 in which the wall means of the chamber means are formed of rigid material and the means of limitation (i) include a gas-tight sliding connection between the chamber means and the conduit means to provide for continued movement of the porous layer contact means toward a porous layer of material after contact of the edge of the margins of the wall means of the chamber means with the porous layer of material to bring the edge of the margins of the wall means of the porous layer contacting means into contact with the porous layer of material.
 7. The apparatus of claim 6 in which the gas-tight sliding connection between the chambEr means and the conduit means includes resilient means acting between the chamber means and the porous layer contact means for maintaining the edge of the margins of the wall means of the chamber means pressed against the porous layer of material with a pressure greater than that exerted on the porous layer of material by the edge of the porous layer contacting means. 